There exist long materials which can be cut and processed depending on a product to be used and an object. These long materials include metal strips having a predetermined thickness and sheet-like products formed with paper, resin and the like. Each of the materials is, in general, shipped in a state of being wound many times around a core like a coil and overlapped.
The above-described long materials include not only a step of molding a starting material but also many related steps such as a step of winding the material around a core, a step of drawing the thus wound material, a step of gripping and conveying the material, and a step of cutting the material to a required width. The individual steps of handling the long materials are important in enhancing the quality and production efficiency of a final product.
For example, metal strips are used as raw materials for various products such as automobiles, consumer electronics, construction materials, steel furniture, electric components and electron components. The metal strips are different in width and thickness depending on use and available in thickness from several μm of a metal foil to several mm of a metal strip.
Further, a range of metal strip widths are available, for example, from several mm of a slit-processed narrow strip to more than 2 meters of metal coil base material prior to a cutting process.
A device for processing the above-described metal strips includes a slitter line which cuts a wide metal coil base material to a fixed width in the longitudinal direction and winds up the material as multiple strips. In addition, the strip means a unit of the number of strips.
The slitter line is a device in which the metal coil base material is drawn from a rotating roll to cut a strip to a desired width by using a slitter and the strip is again wound up around the rotating roll of the recoiler and processed into a metal strip coil.
On the slitter line, it is important to impart an appropriate winding tensile force to a metal strip which is finally wound up by the roll of the recoiler to give tension, thereby neatly winding the metal strip. Where there is a failure in imparting an appropriate winding tensile force to the metal strip coil, the metal strip coil after processing is wound erroneously or an edge of the thus wound coil is made irregular, thereby exhibiting a poor appearance, which poses a problem.
Therefore, on the slitter line, in order to impart an appropriate winding tensile force to the metal strip coil, for example, there exist a winding tensile force imparting device according to a tension pad method (for example, Patent Document 1) and a device according to a roll tension method (for example, Patent Document 2).
However, in the above-described individual devices, on imparting a winding tensile force, abrasions and smears will adhere on the surface of the strip coil. A problem is also posed such that no winding tensile force can be imparted uniformly to all the strip coils.
Under these circumstances, there exists a winding tensile force imparting device which imparts a sufficient winding tensile force to metal strips. For example, Patent Document 3 has proposed a winding tensile force imparting device.
Here, Patent Document 3 has disclosed a winding tensile force imparting device 100 as shown in FIG. 14(a). The winding tensile force imparting device 100 presses a metal strip vertically and is provided with a tension pad 101 which imparts a tensile force. Further, back-tension imparting elastic rolls 102 and 103, each of which is composed of a closely attached laminated product made up of many rubber-like thin elastic circular disks, are arrayed before and after the tension pad.
The winding tensile force imparting device 100 imparts a sufficient winding tensile force to multiple metal strips in combination of the tension pad 101 with the back tension imparting elastic rolls 102 and 103.
On the other hand, sheet-like products formed with paper, resin and the like are materials used in a printer, a packaging machine and a coater. In order to use the sheet-like products effectively and efficiently, it is important to reliably grip and convey long materials while steps are in progress. At this time, there exists a suction roll device which is used as a device for gripping and conveying them.
The suction roll device is such that sheet-like products are adsorbed on an outer circumferential face of a rotating roll to grip and convey long materials. The suction roll device is provided with a region which develops a negative pressure, thereby generating an adsorption force derived from the negative pressure.
Further, the suction roll device includes a device in which an outer circumferential face of a roll is constituted with a porous body so as not to leave adsorption-derived marks on a sheet-like product to be conveyed. However, fine holes on the outer circumference of the roll are clogged with dust and chemicals. Thus, it is necessary to clean the device in a short period of time, resulting in a decreased operating rate, which poses a problem.
Under these circumstances, there exists a suction roll device which does not leave adsorption marks on a sheet-like product and is also less likely to have clogging of fine holes. For example, Patent Document 4 discloses this type of suction roll device.
At this time, Patent Document 4 discloses a suction roll device 200 shown in FIG. 14(b). The suction roll device 200 is provided with a center shaft 202 supported by a support frame 201 which opposes thereto and a cylindrical porous body 203 which is breathable. A plurality of air paths (not illustrated) are formed between the center shaft 202 and the cylindrical porous body 203 in a circumferential direction, with a predetermined interval kept.
Further, there is formed a suction port 205 which opposes one end opening portion 204 of each of some of the plurality of air paths. A pressuring port 207 which opposes the other end opening portion 206 of each of some of the plurality of air paths which are not communicatively connected with the suction port 205, is also formed.
In the suction roll device 200, a negative pressure developed on the side of the suction port 205 is guided into an air path to generate an adsorption force on an outer circumferential face of the cylindrical porous body 203 outside the air path. Further, a positive pressure formed on the side of the pressuring port 207 is guided into an air path and released outside through the cylindrical porous body 203, by which dust and other matter adhered on fine holes are released outside.
The suction roll device also includes a device which is able to adjust a suction width according to the width of a sheet-like product; for example, the suction roll device disclosed in Patent Document 5 exists.
At this time, Patent Document 5 discloses a suction roll device 300 which is shown in FIG. 15. The suction roll device 300 is provided with an external cylinder 301 which rotates freely and an internal cylinder 302 which is fixed. Further, there is provided a driving shaft 303 having a suction port inside the internal cylinder 302, and there is also formed a partition strip 304 which is able to move axially inside the internal cylinder.
Further, the suction roll device 300 allows the partition strip 304 to move inside the internal cylinder by rotational movement of the driving shaft 303, thereby making it possible to adjust a range to be sucked from an opening portion 305.